Corybas macranthus COMMON NAME Spider Orchid SYNONYMS Corysanthes macrantha (Hook.f.) Hook.f.; Nematoceras macranthum Hook.f. FAMILY Orchidaceae AUTHORITY Corybas macranthus (Hook.f.) Rchb.f., FLORA CATEGORY Vascular – Native ENDEMIC TAXON Yes ENDEMIC GENUS Palliser Bay. Oct 1994. Photographer: Jeremy No Rolfe ENDEMIC FAMILY No STRUCTURAL CLASS Orchids NVS CODE NEMMAC CHROMOSOME NUMBER 2n = 36 CURRENT CONSERVATION STATUS 2012 | Not Threatened Rimutaka Incline. Oct 1994. Photographer: Jeremy Rolfe PREVIOUS CONSERVATION STATUSES 2009 | Not Threatened 2004 | Not Threatened DISTRIBUTION Endemic. North, South. Stewart, Chatham, Auckland and Campbell Islands HABITAT Lowland to subalpine (up to 1200 m a.s.l.) usually in damp, shaded to well-lit seepages, or in shaded sites under tall forest or associated with rock overhangs (then often in very dry sites). Favouring base-rich substrates such as calcareous mudstones, siltstones, limestones, dolomite or marble; also on basalt and basaltic-andesites, and soils derived from these. FEATURES Terrestrial, tuberous, spring to summer green perennial forming dense colonies. Plant at flowering 40-100 mm tall. Leaf solitary, distinctly petiolate, petiole hyaline to white, more or less fleshy up to 60 mm long, suberect, ascending; lamina firmly fleshy, up to 40 x 40 mm, mostly green flecked or spotted with purple, or dark green above, silvery green to white beneath, orbicular to oblong-oval, apiculate, base rounded. Floral bract minute, < ovary, narrowly deltoid, initially closely sheathing spreading at flower anthesis. Dorsal sepal mostly shorter than labellum, hyaline yellow-green to greenish-white flecked with crimson or completely wine red, rather long and narrow-lanceolate, acute to shortly acuminate, arching over tubular portion of labellum; lateral sepals dark pink to crimson, filiform, greatly exceeding labellum. Petals similar to lateral sepals but usually much shorter. Labellum completely dark maroon-black or wine red, or dark maroon-black with a greenish throat, auriculate at base, lamina abruptly deflexed, funnelform, broadly expanded all round, margin minutely denticulate with a median apiculus, inner surface rough with short, sharp, retrorse papillae SIMILAR TAXA The stout, fleshy leaf which is usually held up above the flower, and widely flaring trumpet shaped dark maroon- black or wine red labellum, and very narrowly lanceolate dorsal sepal distinguish this species from all except the little known Corybas papillosus. Corybas papillosus differs from C. macranthus mainly by its bicoloured labellum (dark red to purple-red in the upper half, pale pink grading through to whitish in the lower half). FLOWERING September - January FLOWER COLOURS Red/Pink, Yellow FRUITING October - February PROPAGATION TECHNIQUE Difficult - should not be removed from the wild. Can be grown in basic orchid mix consists of 2 parts medium coarse sand, ideally clean river sand; 2 parts soil, humus or leaf-mould; 1 part weathered sawdust or rotting wood; 1 part granulated bark. Many Corybas thrive when more leaf-mould is added, and the plants grown in 50-70% shade, in the cooler, darker end of the shade-house, in pots kept moist throughout the growing period. ETYMOLOGY corybas: Helmet flower WHERE TO BUY Not commercially available TAXONOMIC NOTES Considerable research is underway to investigate the validity of the segregate genera split from Corybas R.Br. by Jones et al. (2002). Whilst much of that work has yet to be published, on advice from Australian Orchidologists Peter Weston and Stephen Hopper (pers. comm., July 2011, November 2014), all of the segregate genera recognised for New Zealand by Jones et al. (2002) are returned to Corybas. Recently Lehnebach (2016) has made three combinations for those Nematoceras lacking valid names in Corybas. This action now enables the full transfer of Nematoceras back to Corybas. However, as of writing, a formal publication rejecting the segregation of Corybas by Jones et al. (2002) has yet to be published. Lehnebach cites an unpublished PhD (Lyon 2014) that indicates this move is imminent. ATTRIBUTION Fact Sheet prepared for NZPCN by P.J. de Lange 14 April 2007. Description adapted from Moore and Edgar (1970). REFERENCES AND FURTHER READING Jones, D.L.; Clements, M.A.; Sharma, I.K.; Mackenzie, A.M.; Molloy, B.P.J. 2002: Nomenclatural notes arising from studies into the Tribe Diurideae (Orchidaceae). The Orchadian 13: 437-468. Lehnebach, C. 2016: New combinations and a replacement name for three New Zealand spider orchids (Corybas). The New Zealand Native Orchid Journal 139. 4-5. Lyon, S. P. 2014: Molecular systematics, biogeography, and mycorrhizal associations in the Acianthinae (Orchidaceae), with a focus on the genus Corybas. PhD Thesis, University of Wisconsin-Madison. USA. Moore, L.B.; Edgar, E. 1970: Flora of New Zealand. Vol. II. Government Printer, Wellington. CITATION Please cite as: de Lange, P.J. (Year at time of access): Corybas macranthus Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/corybas-macranthus/ (Date website was queried) MORE INFORMATION https://www.nzpcn.org.nz/flora/species/corybas-macranthus/.